Question: "What is the quantity in kilograms per cubic metre using the symbol p?"
Paraphrase: "What is the quantity in kilograms per cubic metre the usage of the symbol p?"
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q844211 wdt:P111 ?answer . ?answer wdt:P416 ?x FILTER(contains(?x , 'ρ'))}